1. Field of the Invention
This invention relates to poly(parabanic acid film coated with an acrylic adhesive and to laminates useful as circuit boards made therefrom.
2. Prior Art
Poly(parabanic acids) and films thereof suitable for use in this invention are shown by Patton U.S. Pat. Nos. 3,591,562 and 3,661,859 and in Exxon Chemical Co. trade literature (e.g., "PPA Poly(Parabanic Acids)", 20 pp., February, 1973). The two Patton patents and the specified trade literature are incorporated herein by reference.
The use of acrylic adhesives with polyimide film is shown in my U.S. Pat. No. 3,900,662, also incorporated herein by reference.
Poly(parabanic acid) polymer films are available commercially from Exxon Chemical Co. under the trade name Tredlon.RTM..